U.S. Pat. No. 5,538,692 to Joannou describes an ionizing type air cleaner having an exposed ionizing needle and a collector element in the form of a charged, partially conducting, surface. (See FIG. 1) Ions released from the needle spread-out through the air of the surrounding environment in the form of an “ion wind”, charging particles of dust present therein. By reason of the charge on the collecting surface, such dust particles are drawn to and become attached upon the collecting surface. Dust removed from the air in this manner may be readily disposed of by simply wiping the collecting surface with a rag or the like.
Although the collecting plate will attract and hold a substantial part of the dust present in the air flow, nevertheless some dust and oily aerosols will still be present in the air flow that moves past the collecting plate. A number of these particles will still be charged. It has been found that such ionized particles as are not collected on the collecting plate have a tendency to collect on adjacent uncharged surfaces, such as walls. Over time, the collection of particles on wall surfaces can become visible as a discoloration. This is an undesirable effect. This disadvantage arises because this air cleaner acts as a “fountain of ions” with its collection surface positioned beneath the ion source, requiring ions to flow outwardly before being collected.
A need exists for an ionization-based air cleaner that has a reduced tendency to produce discoloration on adjacent surfaces. The invention herein addresses that objective. This invention is a continuation-in-part of U.S. application Ser. No. 10/067,433 filed Feb. 10, 2002 (the contents of which are adopted herein by reference) which application partially provides part of the disclosure and solution set-out herein, now U.S. Pat. No. 6,919,053.
It has been disclosed in U.S. Pat. Nos. 6,176,977, and 6,312,507 to Taylor et al to provide a pointed ion source upstream in an ion induced airflow, with washer-like ring electrodes positioned downstream. Dust charged by ions is collected on the flat surfaces of the ring-like electrodes facing the ion source as well as between plates.
The design of U.S. Pat. No. 6,176,977 does not, however, address confining the ion-wind induced airflow, or providing an airflow path that will minimize interference with such airflow. The invention disclosed herein, however, incorporates such features.
The invention in its general form will first be described and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification.